How to service the Yamaha P-320 turntable

With vinyl records making a bit of a come back, my own audio system has been seeing regular use.. The system is nothing startling and in fact its got a low output Sony amplifier that just puts out 20 watts per channel.

The speakers to me are special being Goodmans Mezzo 2, said to be the best of the best when they came onto the audio scene around thirty years back?
The turntable is a Yamaha P-320 and looking at its inside, plus the cast alloy turntable disc, its clear to see Yamaha  made that well too.

http://ckdboats.blogspot.com/2011/09/speaking-to-your-selfhow-hard-can-that.html

The Yamaha P-320 turntable, bought new in July 1990 from Hamrad with the Sony multi function amplifier, its now 22 years old.

This was writen about by me before, about two years back.

http://www.blogger.com/blogger.g?blogID=696865986115363040#editor/target=post;postID=4034355978330670446

The turntable rubber mat when removed reveals the very nice alloy disc, to the left is the access to the rubber band drive belt, which fits around the the underside of the disc and around the drive motor rotor.

Recently I have noticed a noise in the left hand speaker, I checked inside both speakers and discovered nothing, switching left to right did not help, neither did new quality twin flex cables, I then supspected a fault in the Sony amplifier?

Disconnect the power supply and remove the complete stylus mount when your working on the table.

 I then thought to check the turntable out, making it 100% level certainally helped, I increased the anti skate bias as well, the sound was by now much smoother and clearer, I used a Matt Bianco album to get a good selection of musical instrument sounds.

When the alloy table was removed, I found a probable cause of noise right away, the rubber belt drive pin was quite loose, plus it had a central and uneven build up of rubber that had come off the two belts used in its lifetime, this I managed to remove with my finger nail. On closer inspection I found the rubber bushes around the mount screws had shrunk.

I then removed each screw one at a time and replaced them using a thin rubber washer, the drive pin was now secure. Note the by now clean drive pin surface. New drive belts are available

locally in Cape Town.

With the bottom cover screws removed, this includes the four spring mounted rubber feet, I could access the works and see if any obvious faults existed?
The drive motor is the small round item on the right with yellow,white,black and red wires coming from it.

Remove all 10 screws, lift the metal cover from the side closest to you in the picture, hinge it back and then find the small earth cable in the back left hand corner, do not break the cable or its soldered joints.

The Yamaha drive motor, I brushed the inside of the player to move dust, then vacumed it clean.

To refit the alloy table, mount the drive belt on it, then fit the table on the center pin, you can then access the belt and move it over to the drive pin, a toothpick will suit this job.

The model number.

Ready to play again, make sure you refit the rubber mat the right way up.

Check the three crossed tuning forks, proof that its a real Yamaha!

Yamaha P-320 turntable info.

A test play had me listening to some clean and pure audio sound, the fix worked but I still get feedback from the left speaker when the stylus is down and I tap the plastic dust cover lightly, why?

I now suspect the stylus fitting, as fitting another stylus reduced the side noise.

Roy

Technical stuff.

Specifications

Drive system: belt drive

Motor: v servo dc motor

Platter: 300mm, 0.9kg, diecast aluminium

Speeds: 33 and 45rpm

Signal to noise ratio: better than 70dB

Wow and flutter: less than 0.04% WRMS

Tonearm: swinging straight arm

Effective length: 222mm

Overhang: 16mm

Tracking force: static balanced 0-3g

Effective mass: 11g

Offset angle: 23 degrees

Dimensions: 435 x 111 x 378mm

Weight: 5.8kg

Downloads

service manual (en)

How to repair a British Seagull outboard that runs slowly

Recently we did a back outboard test to see what performance we can get from old and new outboards, I say old and new but the old engine was 51 years old and the newest about 6 years old, its relative? The larger Yamaha 5hp motor gave us 10.1 knots and the Mercury 2.5hp motor gave 5.6 knots, so the smaller engine was doing rather well.

The test was less successful  than we expected, being let down by both Seagull motors, both had the same sort of  misfire and would not reach anywhere near full revs, they needed a lot of choke and a wide throttle.

http://ckdboats.blogspot.com/2012/06/testing-times-for-marine-outboards.html
I contacted John at SOS (save our seagulls) in Essex, England, he suggested there was dirt in the carburetor jet? Cleaning one carb sorted that motor out and it was soon running cleanly and the choke could be opened on firing right away.

The other motor refused to run properly, even after stripping the carb down twice, the only indication I could get was when the fuel bowl was manually over filled, the problem went away untill the fuel level went down, now what?  What was this problem all about, well I had already raised the level of the float in the petrol bowl, what else can I now do?

The air compensator is the round cover on the carburetor. The motor is a 4.5hp unit and is around 35 years old?

Checking the workshop manual I saw that on the Villiers carburetor page there was one difference between  the two carbs on the Seagull motors, the one that ran well had an Air Compensator while the one that still would not run well did not, I wonder ?  thought I.

Note that air correction hole, I think without the compensator being fitted, too much air is fed into the hole, the pressure then upsets the fuel level?

The new plastic air compensator had arrived the same day I discovered its need. Not cheap at about 8 Pounds Sterling, plus pack and post, a Pound to write the invoice into Pay-Pal and when it landed, the packeage was opened by the customs and a 20% duty plus 14% vat was added. I think this bit of plastic cost me R230 and more!

I removed the air compensator from the one motor and fitted it to the motor that would not run properly, it started right away and ran cleanly! So we can now complete the back to back test, this time a blog viewer has also offered me his electric outboard, we can try that off his battery and also a solar panel designed to suit the electric outboard.

How good is this.

Roy

Refitting a Hillman Imps 998cc steel liners

The Imps steel liners should be bonded into the alloy block using Loctite 648 retaining fluid, not cheap but its the right product for the job. If for any reason you need to remove those liners, a mandrel will require making as a press tool, another size of liner can be turned down to fit inside the Imps liner. You will require the use of a standard garage hydraulic press to do the liner removal, I was told its an easy job this way.

Loctite 648 retaining fluid.

The alloy Imp block as it looks after the original liners are machined away, this block was later welded and the alloy liners support holes were distorted about 0.003" meaning the steel liners would no longer fit.

In the case of the 998cc block made here, the liners were not exactly level and I asked they be pressed out and I would refit them myself.

The question now was how do I get those new steel liners to fit back in the holes they came out of? They were numbered using a black felt tipped pen.

The perfect tool was a low priced solution to the question, the flapper sander is 80mm in diameter, the alloy hole is 77mm (about) and with a bit of hand reforming, I made the flapper sander fit. Using a Bosch 500 watt electric drill and a low speed, I was able to lightly sand the deformed alloy untill the steel liners fitted.

Low speed is very important, move the drill up and down as you sand, never stay in one position while the drill is working.

We need a drop in fit, this is because we need to coat the liners with the Loctite 648, then refit by hand before lightly bolting down a re faced cylinder head to give us a perfectly flat set of four 998cc Imp steel liners.

Looking inside when the liners are in place, I have used a good Mk1 cylinder head to hold the loose liners down.

The liners are back in the block, prooving we can do this kind of machine work ourselves. The welding on the top of the block was milled off first.

The first fit was done on a warm afternoon, the next day they would not come out, such was the fit and with a by now cold block, they had become fast. I warmed the alloy block up in the morning sun (its winter) then I was able to remove the liners again. I lightly dressed the alloy sockets down with the flapper sander and was then able to fit and remove the liners.

Block saved? well we still need to check the crank journals are true but we are becoming close to having a good 998cc Imp block.

I have just checked the 998cc Imp block more fully, sort of one thing at a time, its as I suspected , the block is bent. Down about 0.015' in the center and more to the rear of the central journal. This in effect means the next step is to skim top and bottom surfaces and then line bore the journal, not a job Roy can do. It may just be possible that the line bore can just be on the center journal, if so its easy, they remove metal from the cap face, the cap then is higher into the block and means they can rebore, simple but what will it cost?

Roy

The Queens Jubilee day for us

Seen here on a winters day and having a beer is Athol, skipper and owner of yacht Perazim, he joined us for a sail past the East Fort in Hout Bay to pay our respects to the Queen.

John off  Rosie Dry supplied the beer.

The HBYC posted some pictures as well

http://www.hbycclub.blogspot.com/

Another John, this time off yacht Polaris joined us too.

John was hanging on to Druma our dog for a while, we then put the life vest on Druma, we all relaxed a lot more then!

We had been informed that the East Fort's old cannons would be fired at 3pm, it never happened, we were back in the harbour by the time they fired them.

We at least flew some flags, at the back of the boat was the OCC Port Officers flag, from the starboard side we flew the South African, then Union flags, followed by the OCC, HBYC and TBA burgees.

How nice was this.

Roy

How to mill the top edge of a Hillman Imp Timing cover

The timing cover should be milled at the same time as the block should it be re surfaced? In this case it was forgotton and stood proud by about 0.008" or so?
When this is the case, the cylinder head gasket will not tighten level and the excess alloy must be removed.

The jig or template I made for the removal of alloy on the block edges has been re cut to expose the area over the timing chain cover. Even with bolts some distance away, the 32mm thick MDF (supawood) stays perfectly flat, note the plastic safety glasses, a must have when milling metal is concerned. Thinner MDF should also work, say down to 18mm thick but thicker is better.

Having done much smaller areas the day before, I knew this was going to work, the process was now understood and went very quickly. Do not over tighten the bolts, you may introduce distortion?

The Makita 3612 router, this model has an auto brake and stops very quickly, recomended!

The 13mm milling cutter, a tungsten tipped type will also work but the finish will not be as smooth?

The template will be stored away for other work on alloy Hillman Imp blocks.

The finished job, I took around three cuts to make the load on the milling cutter less, this way you can slowly move down to the required depth.

Click on the pictures, they should enlarge.

The milled Hillman Imp alloy block and timing cover. This fix cost me nothing, all the tools were to hand, scrap MDF was the template material and I did not have the expense of a machine shop or the traveling time there and back.

Next I will show you how I fitted the 998cc steel liners into the alloy sockets which had distorted some 0.003" ?

Works for me!

Roy

A Didi Retro 29 boat test (before we even build one)

Justin Phillips has really got his mind into the new design by Dudley Dix, so much so he seems to have been on the boat and sailing it in our local regattas!

Check the link: http://sayachts.blogspot.com/

Justin has been reviewing yachts by many designers that are South African specific, they were all built here, many were also designed by South Africans as well.

We will soon be cutting the kit for boat 001, it will be built locally and in
Hout Bay, South Africa.


Roy

Milling an Imp block, part three

This can all be done a pro machine shop but the idea in this case was to proove we can also do these small jobs ourselves. You need the tools of course but they have become very low priced these days, always by the best quality you can, not the lowest price.

Seen here we now just need to set the milling tool to the block face, the tool can not go any deeper.

I was able to secure the template using standard Hillman Imp head bolts once I had made up spacers from MDF offcuts.

This is the hardened steel 13mm milling bit, it cuts cleaner than a tungsten tipped router cutter.

The 3612 Makita router is an industrial grade machine, smaller sized tools will work but the ones that will take the 13mm cutter shaft will be best suited.

The excess weld as milled away, note the plastic glasses for eye protection.

The idea worked 100%, you will need to move the bolts around to allow the base of the router room to move. Do not overtighten the template bolts, distortion may be the result?

 

To be continued in part four.

Roy

Milling the top of an Imp engine block yourself

The idea to save the 998cc block was on that could either work or fail, given my time to myself was free and the parts were paid for, what can I loose? Three main issues were obvious, the steel liners no longer fitted the holes they came out of (numbered with a black felt tip pen) the top landing of the block needed machining flat and I needed to see if the block was flat or twisted?

I decided that taking it one job at a time was the best way to start, cleaning the top of the block would be my first task.

I wanted to use a large Makita router and a 13mm milling bit, tools in my workshop and right for the job.  The board under the gasket is 32mm MDF (supawood) and was perfect for using as a bolted down template on the top of the block. The gasket was the template for the cylinder head bolts I needed to use. The MDF in 32 mm was in stock, you could use thinner but the thicker will give better results due to its stiffness.

Drilled through with a 10mm twist bit, when vacumed clean we were ready for the next stage.

It is now jigsaw time, after setting out where the welds needed cleaning up, I could drill the cutouts corners and then saw the hole free.

Template and block are about to be bolted together after this stage.

When the template and block were together, the welds were seen to be accessable, the idea was then to mill the weld away with the milling tool.

Continues in part three.

Roy

How to mill a Hillman Imp block top edge after welding?

Part one:

This one came about after a Mk2 block with a 998cc conversion, saw damage after various complications with both the height of the liners and a sport wills ringed head that was not as perfect as was thought.

Check the three welds on the top edge of the Hillman Imp alloy 998cc block. All pictures should enlarge when you click on them.

The new steel liners in the block looked great, done by a local machine shop, it was to become a learning curve for all involved, I later prooved the linings had not been glued in level, they were out of level from 0.0005" to 0.003". I had them pressed out and refitted them myself with Loctite 648 bonding liquid, using a bolted down 170 series sport cylinder head that had been faced skimmed as the press tool.

The repair weld has been cleaned down  with a disc grinder to clean it up but still requires a final milling to the level of the block, note the hard steel thread insert.

This method prooved to work and I found the liners were at the required plus 0.002" hight above the block face after doing it my way. However, this was not the end of the story and the engine never did get sorted in time to ship to Scotland with its sprint prepared body. I was left holding the engine parts as a buy back of what they would cost in the UK, a gamble if they prooved to be of no use?

The block had cracked in two places when the head was tightened down.

It became a long story and right now one I will not cover fully, the issue became more could I get the parts with what was by now a three times welded alloy block to work? The machine shop called to say that the loose liners would no longer fit the bores in the block they came out of, they were out by around 0.003", I called the job off and then collected the engine in bits and brought them back to my own workshop.

The second crack. A damaged block like this may just be dumped in the UK but not here in South Africa, they are very scarce and in the case of this 998cc block, a great deal of money has been invested in it already.

 

 This was secondary welding, required as stop ends when we fitted the thread inserts, a few leaked due to thin metal on the inside of the block, so all thread ends were welded shut.

I then looked at the matter in a series of whats important (pun?) I fitted the crank, it turned ok but was less free than before welding, it will I hope bed in, we may end up doing a line bore job? I then needed to check the top landing, fitting a good cylinder head is a good way to start but there was excess welding on the top of the block that needed milling off, can I do that I thought!

Can this 998cc Imp block be made to run again?

Pictures (lots) and the rest of the story to follow in part two.

Roy